Saturday, May 28, 2005

Here is part one of a nice interview with Bill James over at Baseball Digest Daily.

Two interesting points.

First, James' comments about bunting:

'...the general argument against the bunt seems unpersuasive to me. The essential argument against the bunt is that the number of expected runs scored after a bunt attempt goes down in almost all situations when a bunt is used, and the expectation of scoring one run goes up only in a few situations.

But this argument is unpersuasive, to me, because it assumes that there are two possible outcomes of a bunt: a “successful” bunt, which trades a base for and out, and an “unsuccessful” bunt, which involves an out with no gain. In reality, there are about a dozen fairly common outcomes of a bunt attempt. The most common of those is a foul ball, but others include a base hit, a fielder’s choice/all safe, a pop out, a pop out into a double play, an error on the third baseman, and a hit plus an error on the third baseman, or the second baseman if you’re talking about a drag bunt.'

James is of course correct that the argument against the bunt is generally that the run potential decreases after a bunt. For example, using my Desktop Big League Manager, you can quickly see how this works.

The first table below shows the odds with which the sacrifice would have to be successful given a typical hitter (1999-2002) in order to increase the chances of scoring a single run and to maximize the number of runs in the inning. A value of "No" indicates that even if the sacrifice is successful the odds of scoring a single run or maximizing runs goes down.

As you can see the only time it makes sense is when runners are on first and second with nobody out and you need one run to tie or win the game. And even then you need to be pretty certain that the hitter can get the bunt down.

However, with a pitcher at bat the odds change since the chances of a pitcher advancing a hitter with a hit go down.

Obviously, with a pitcher who can actually get down the bunt it makes sense to do so not only with runners on first and second and nobody out but also a runner on second and nobody out, and even a runner on first when you need a run.

And James is also correct in saying that these calculations are based on only two of the several possible outcomes when a batter squares around to bunt. His comments made me curious to find out how often some of those other outcomes occur.

I took a look at the 2004 play by play data and found that there were 1,731 successful sacrifice bunts in the majors in 2004, an average of 58 per team. Montreal had the most at 100 while Boston had just 12. I also found that there were 515 bunt grounders recorded when there were runners on base, less than two outs, and where the batter was not credited with a sacrifice. Now, it's difficult to gaguge intent from these play-by-play records since some or even most of these may in fact have been instances of hitters bunting for hits with runners on. That said, here were the results of those 515 bunt grounders.

Positive OutcomesErrors: 12Singles + One or more errors: 29Singles: 194Fielder's Choice + One or more errors: 4Force out + One or more errors: 2

So we can throw out the last entry in that list since the batter was out and yet the official scorer did not rule a sacrifice. So that leaves us with 466 bunt grounders. However, to this list we can add the 162 times a batter struck out on a two-strike bunt attempt with runners on and safely assume that the vast majority of these were perpetrated by pitchers attempting to bunt with two strikes.

So assuming that all rest were sacrifice attempts (which is unrealistic) the odds of a successful sacrifice (taking into account all positive outcomes for the offense) is:

(1731+194+29+12+4+2)/(1731+194+29+12+4+2+29+177+21+49+162) = 81.8%

If you assume that none of the singles were sacrifice attempts the percentage drops to 80.2%. So we can be pretty confident that around 81% of the time a sacrifice attempt is successful. Given this number, however, you can still see from the tables above that there are only a couple of situations where a sacrifice attempt to warranted (obviously the actual percentage will change when considering double plays and errors but since the number of both are similar it seems like these would cancel each other out for the most part). So based on this I'm still pretty comfortable taking Earl Weaver's side in this argument.

So assuming that all the singles were sac attempts, the odds of the other outcomes are:

One of the interesting things here is that the odds of striking out are almost six times greater than the odds of bunting into a double play, which is ostensibly the reason managers direct their pitchers to try and bunt with two strikes. Incidentally, the team leaders in striking out while bunting were:

CIN 16LAN 15MIL 12PHI 12ATL 11HOU 10SDN 9COL 9NYN 8SLN 7

Second, James' has a nice description of the decreasing relative importance of defense over the years which parallels Stephen Jay Gould's argument about .400 hitting. Essentially, as a system stabilizes variation decreases. Variation in fielding has decreased as the game has developed (due to better equipment, standard positioning and a universal set of styles of play not to mention the increase in homeruns and strikeouts), and so there is a smaller relative difference in defensive play across teams. It's not that defense is any less important - after all if you put me at third base for a major league team you'd quickly see why - but it is the case that major league teams don't need to spend as many resources finding top flight defensive players since the number of runs a great defender saves over and above an average defender is smaller than the number of runs a great offensive players produces over and above a mediocre one. I believe this is the case for offense as well but the magnitude of the difference is smaller.